With the ionospheric electron density profiles derived from the COSMIC radio occultation mission during 2010 to 2014, the qualities of these profiles were checked comprehensively using four quality control parameters which consider only the profile′s own characteristics. The spatial and temporal distributions of the qualities of the profiles were analyzed accordingly. It is found that the qualities of the profiles are the highest over the high-latitude regions, followed by the low-latitude regions and the lowest over the mid-latitude regions. This may be due to the existence of the equatorial anomaly of the electron density distribution near the magnetic equator. The seasonal variation of the qualities of the profiles is distinct, which shows a significantly higher rejection ratio in winter and spring than in summer and autumn over both of the two hemispheres. In addition, the rejection ratio of the profiles is significantly lower in daytime than in nighttime, and it has great changes occurring at twilight demarcations. The peak electron densities and the corresponding peak heights derived from the qualified profiles are significantly higher over magnetic equator than over other regions, which shows a “double hump” phenomenon.